Collapsible pond



1952 v. H. HASSELQUIST 2,

COLLAPSIBLE POND Filed Jan. 1'7, 1948 2 Sl-lEETS-Sl-IEET 1 Patented Nov.4, 1952 UNITED STATES *ATENT OFFICE ApplicationJanuary 17, 1948, SerialNo. 2 931- 7' Claims: 1.

Thisfinvention relates. to collapsible containers for liquid or otherflowable material and especially to portable wading or" swimming pools;skating ponds, portable. storage" tanks'ior Water and other liquids;

Objects of the invention" are: t'oprovide an impr'ovedcollapsiblecontainer of rectangular; circular or otherwise curved, or other desiredform having a' flexible peripheral wall'lifted to the posi ti'on'. foruse" and' supported in antupright' condition'solely by.'ahydrostaticheadv oficontained liquidj to provide. for restraining the wall againstoutward rolling; to provide. in a rectangular container'forresistinglocalized outward bowing of the flexible wall intermediate the'corners'thereof; to provide for foldability ofa relatively"stifi,"peripheralcollar orupstandin jdam 'a'tthe' upper marginroflthe wall or innerrimofi the container; to provide'ior' water-tightness to provide'forrconvenience of. emptying the containerrand to provide'forsimplicity ofconstruction, convenience of manufacture and storage,portabilityiandilight weight; and attractive appearance.

These and other objects .and'advantages of the invention'will beapparent fromfthe .followingde scripti'on.

Inthe accompanyingidrawings, which forma part of this.specificationla'nddn which like numerais" are" employed to designatelike parts throughoutthe' same;

Fig.1 is a plan .view from above of a collapsible container of"circular'form, constructed: in accordancewith and embo dyingtheinvention;

Fig". 2"is a? sidet'elevation'ofthefcontainer,

Fig: 3"ista sectional'vi'ewonian enlarged scale.

taken'a1ong1ine3-"3 ofFig. 1; .partsibeing broken away,

Figf 4 is a. sectional. side elevation on 1 an: en'- larged'scale' ofthecontainer disposed on an inclined'ortilted supporting surface;

Fig. 5 is a plan view of'a collar or dam'before attachment to the innerrim of the container, parts being broken away,

Fig: Gis-a-sectional View on'an enlargedscale taken'along line =B-6 ofFig; 5;

Fig: '7'is a plan view of a modified construction of the embodiment of'Fig'; land being'of square form with rounded corners,

Fig. 8' is a side elevation of Fig. 7'; and- Fig..9 "isa sectional sideelevation on an en larged scale oi'a' further modification havin themarginal wall hydraulically maintained in the uprighti conditionindependent of the main body ofzf liquid 'in the container, parts beingbroken aways In'the, illustrative embodiment 'of'the' invention shown inFigs. 1 to 6' inclusive, vthe container includes a base or bottoml5"'whi'ch' may. be of cire cular form. of the desired dimensions, andis of flexible. fluid tight' sheetmaterial, preferably'rubber-likewater-proof" material; the base being made of one or more'thickn'essesof the material; The rubber-like material may be rubber, naturaloi-"syn'th'etic, or it maybe plasticizedipolyvinyl chloride or otherpolymer of' a rubber like nature. The" sheet material maybe'reinforcedj' ,if desired, asby'suitable woven or. lc nitt'ed'fabricor other distensible reinforcin'gmaterial vunitedtherewith.

The joinder'ofthe' partsofthe container may be effected in a sealedmanner as .by the application' of heat' and" pressure. whereby. theabutting surfacesof'the joints are fused together.

At'it's periphery, the'cont'ainer has a circumferentiallyjcontinuous.marginalwall or peripheral sidewall I8" of suitable flexiblefiuid tight. material with or withoutfabric reinforcement-anddn one'or'more thicknesses united "in sealing relation with. the base [5,desirably in radially. unbroken continuation' ofl the. material? of Ithe. base. The wall lsihas ai'ullness sothat'the wall "isoutward ly'a'ndupwardly bulged relativetothe baseflto a flatlyfarched contour at alllpositions, .when under a hydrostatichead. or. pressure ofcontained.liqmet, ,as shown in the drawings. Thenwalliltterminatesin an upper:margin. l'ilof Y gradually decreasing curvature which.- margin floats on.the Wateriby the action of Itheupwardly-directed.pres sure oftheliquid'upon thewalll. Thistcons-truce tion provides anopen-toppedarrangement hav--- ing a peripheral, ,flatly. arched.rimofsubstantiall lateral extent, as "shown. in the drawings whichconstruction permits local rise and fall .ottheup,

per: margin. l i with the surgeoflthe .liquid in-float-- ingrelationtherewith while presenting-resistance to circumferential distortion.

The margin I! having annular stifiening means for example, as canvasimpregnatedorcoated'with suitable rubberlike'm'aterial. The strip24is'fo'1d ed 1 with 7 its overlapping sidema'rgins positionedtogetherr' at andsecured together as bya double-row of stitches 26, 25of filamentary material, or a suitable rubber cement, or both, as shownespecially in Figs. 5 and 6. A flexible, reinforcing wire 27 of copper,brass, steel or other suitable metal material is disposed longitudinallybetween the folds of the strip 25 with longitudinally spaced-apart,open-looped reaches 29, 29 arranged transversely of the stripsubstantially from margin 28 to margin 25. The closed end portions ofthe looped reaches of the wire 27 may be engaged by the stitches 26, 25.The folds of the strip 24 intermediate the margins 25, 28 are adheredtogether for holding the wire 2'! in position. The ends of the strip21'. are secured to one another as by stitches, or an adhesive. or both.The construction produces a foldable, closed, collar structure.

The collar 23 is bent intermediate the margins 25, 28 to an L-shape insection, as shown especially in Fig. 3, providing a seating portion 30and an upright leg portion 3 I, the flexibility and give of the canvasand the distortability of the loopedwire arrangement facilitating thebending. The collar may be attached at its seating portion 30 to theouter face of the upper margin I7 as by stitches, or a suitableadhesive, or both. The leg portion 3| projects upwardly from the outerface of the wall I6.

The collar 23, in addition to its hoop-stifiening action, thus providesfor holding the contained water at the desired level. The flexibleconstruction of the strip also facilitates bending the latter to andfrom a substantially flat, annular form for storage and packagingpurposes.

The invention provides flexible restraining means I8 extending betweenthe upper margin I! and the base I5, and, in the filled condition of thecontainer, the means I8 is positionable diagonally inward and downwardfrom such margin to the base. The restraining means functions in themanner of a stay to restrain outward rolling of the marginal wall I 5under the hydrostatic pressure and to restrain outward bowing at localregions along the wall IE, all of which facilitates maintaining thedesired form of the container. At the same time, the stay permits therising and falling of the upper margin of the wall to accommodate thewater level and surges of the water.

In the embodiment of Figs. 1 to 5 inclusive, the

restraining means I8 may be a circumferentially continuous stay member.The stay I8 may be made of one or more thicknesses of flexible,substantially inextensible, sheet material such, for example, as woventextile fabric coated or impregnated with rubber or other rubber-likematerial, and may have a plurality of spaced-apart apertures I9, I9 tofacilitate the passage of contained liquid such as water through thestay. The stay is suitably attached at I8a to the base I5 inwardly ofthe periphery of the upper margin I1, and at I81) to the upper margin Il providing with the base and the wall an annular peripheral chamber 32in communication with the main body of water of the container. The stayis dimensioned so that it is desirably in a taut condition and indiagonal relation to the base, when the wall I6 is positioned in theflatly arched condition for use, as shown in the drawings.

The attachment of the flexible stay I8 to the upper margin I l and tothe base I5 together with the diagonal disposition and the peripheralcontinuity of the stay assures effectively restraining outward rollingand resisting localized distortion or outward bowing of the wall,whether the container be positioned on a horizontal supporting surface,as shown in Figs. 1 to 3 inclusive, or on a supporting surface 28 tiltedor inclined at an angle 2! with respect to a horizontal plane at 22, asshown in Fig. i. The restraining action of the stay IS in cooperationwith the hoop-stiffening action of the dam 28 facilitates maintainingthe desired shape of the container and the outwardly and upwardly archedform of the marginal wall, especially when the container is positionedon an inclined supporting surface 29.

In the operation of the container which is adapted for packaging andstoring in a compact, folded disposition. the same may be unfolded andspread out in the collapsed condition. Water 01' other liquid isadmitted through the top opening defined by the dam 23 and wall margin II into the space of the container, which water builds up in depth andflows through the apertures I9, I9 in the stay I8 into the space of theperipheral chamber 3.2. Any air in the chamber 32 may be vented to theatmosphere through a plurality of spaced-apart vents 33, 33 in the stayimmediately adjacent the upper margin IT.

The pressure head of water produces hydrostatic forces acting cn theinner surface of the marginal wall to lift the wall IS away from thebase to the upright position, while the wall by virtue of its fullnessand flexibility tends to assume a flatly arched form, and at the sametime the base I5 becomes taut and is pressed against the ground. Thestay I8 swings upwardly about its attachment at Ida to the base with theelevation of the wall It. When the limit of upward movement of the wallIt is reached, the stay is in a taut condition between its margins indiagonal or angular relation to the base, as shown especially in Fig. 3.

Entrapped air may be vented from the peripheral space at 32 through thevents 33, 33 high in the stay I8.

Upon complete filling of the container with water, the level of the mainbody of water is maintained adjacent the top of the dam 23 to provide aliquid pressure head effecting a lifting action on the margin I? beneaththe dam. This assures continuity of support by hydrostatic forces actingupwardly and peripherally on the wall It, particularly at the margin H,to hold wall upright at the desired height, while the upper margin ofthe wall floats upon the contained liquid.

When the container is positioned on sloping ground and filled withwater, as shown in Fig. 4. the hydrostatic forces of the wall It of thelower half at 34 are relatively greater than those of the higher half at35 of the container due to the greater liquid lead. These greater forcestend to roll the bulged wall at the lower half at 34 out wardly towardand upon the ground and tend to distort the circular shape of thecontainer despite the hoop-stiifening action of the dam 23 and theresistance of the upper margin IT to distortion.

The circumferential stay I3 overcomes effectively the objectionableoutward rolling action downside of the wall; since the diagonal stay,being of finite extent between its margins ltd and I322, assumes a tautcondition.

When it is desired to restore the container to the collapsed conditionas for storage purposes, the water may be drained conveniently from thecontainer through a suitable outlet fitting 36 closed by a removableplug 3?. The plug is retained in the space 32 and may be worked into thefitting for closing purposes, the flexible materiall'ofthe.construction-permittingxhis;fl.Thadam: 2'3; zmayxthen-zb eabent':from-1 itsaLi-shapectossa- .subastantially fiatiringishapec-forfacilitatingarfolding: and storing thecontainer;

The modified constructionz l Bio-ffEigs; 'Tta-nd 8lise like-that:oftliecontainer of Fig: :IiteXceptitHatfit: is: of square or-- other.rectangular. form: with. straight: sides... Rounded-'1 corners: may bepIGF- videdi' The flexible restrainingmeansili I ;or-.inner peripheral:stay of B'suitable flexible;,'..substantially.: inextensible;water+tight.materialghasa aipluralityg of spacedeapartropeningsawhichlmayrbe :in:.the: formuofrtransverseslit's: 42, 4.23mitheepassageaofi water: or other. liquid 3 therethroughc. 'Ilhea slits:may terminate closely ad=jacentxthezuppenmarginp 4410i Fth'e wall :43 to.ventszairsfromthesperipheral: space atz-Ml between: the: wall-1 43::and itheastayml'l although additional. 1'. vents may; .be'a provided;-.ii. desired; as; in .thaemb odimentiof rFlig: La. The.:stay"; extendsdiagonally: fromethe; upper? margin 44 adjac'entxthe stiffening: dam: 45to;.the2base ifisat; apositionatiz l'l inwardly ofiftheazmargin .4422,

. The. flexible; stay. 4 l 2 functions; as; described:hereinaboveforthe; stay; lstrwheni the ;-container:r

isfilledwithwater; and cooperates with-thebase:

llfiliand s the dam: 45.: toxrestrain: outward rolling of1the:marginalWall 43:.

Although 1. the; liquid, head: acting;- uniformly; alongthewall k3)at:;each ystraighttside; ordinarily:wouldztendztozbow.on;curveaoutwardlyvthexside andrjdistort thescontainerto-.a-;generally; rounded; form, ,the; stay. 'uniiormlyres-trains:andzcounter- 1 acts; thisi bowing: tendency: thereby facilitatingthemaintenanceof 'thessquare. form'and:preyent inggsubsidence of: the:wall;

Theiwatenmay-f-be;drained from trier-container: by. a suitable:outletgfitting; :3 6 and: plug-i3'lwinthe; basezMi; The dam45:;maybelfoldedeforpstorage: purposesias. discussed hereinaboveiorlthe.:dam-:-

In anothermodification showntqespeciall-yg m5. Eig;.,.9, the:-container,58 {may be of the desirediorma inplan and -.may. be constructed in some:aspects likethe; containerseof Eig s;-- 1: to 8,- inclusive;- but--difiers therefrom several features The .-mar--- ginal-wall 51'-is-zlifted to,- and-,-supportediin the position -for:use bhydrostaticpressure-means in-. e dependentcf-the-mainbodywfdiquidphthecon-g tainer itself, whereby.- an; accessory-stiffening; collar or damis not requi r.edgfor obtaining the desired liquidpressure head:

The restraining means or stay 52 of suitable flexible, fluid-tightmaterial is made without openings ,so ;that thestayprovideszazsubstantially impervious, inner wall of thercontainerg'fiilrfor'holding the main body of 1iquid in vthe latter, and

in cooperation with themarginal wall?! and base 53 provides a closed,annularxchamber 54 eXtend-J' ingr; peripherally. about the container.

' Thegchambierisufilled witltwater andigmaim tainedi under.liquidpressureheadi by a; hollow stack orrstandpipe 55attheaupperimargirijfisin communication with the chamber 54 through thewall 5!. The stack 55 projects upwardly from the marginal wall M. Thestack has self-supporting walls of suitable flexible fluid-tightmaterial, and is dimensioned to provide a substantial pressure head ofcontained liquid acting upwardly for effectively maintaining the wall 5|upright in flatly arched condition for use. Closing or sealing theopen-end oi the stack is not required. The water in the chamber may bedrained through the base 53 by a suitable outlet fitting 51 and plug 58.

In the operation of the container 50, the latter, in a collapsedcondition, is spread out on the mDst'iOr allthe. entrappedlair .withinithe chamber:-

escapingthrough the .stack .during the fillingsope eration. The marginalwall '5 l isethus hydrauli cally. elevatedeto th'e.flatlyarchediposition for use;

1 tautz: and: pivots upwardly about itsi attachment:

to;th'e:loase 5I3understheaactionof!the hydrostatioz forces; as thewater: buildszup in.:. depth: in" the chamber 514's. andzrestrains.outward:rollingixandbowingzofrthe'wall 5i. The -interiortati 6ll ofthe=container 'mayzbefilled: with waterl to the-desired depth zandzmay;be*sfilledircoincid:ntally:v withither chamber;

'Ihezconstruction entire-container: 53 3111115 -prevent'sr'subsidence'zofzthewall andslossxoffcontained? liquid and;assurescontinuit zof.hydrostaticslifts 1 ingrqfQI'GBS-Eflfijhfiwall:independentlyiorathe:levell oi:containedzliqllidxinz the interior;atafill ofither container-s; Thegmainrbodyiof .liquid 'atifiili may erconvenientlydrain'ed-i: through; the; outlet:- fitting 3.6..andrplug3].

Variations.- may be made withoutr departing frormtheascope of theinvention aseitz-iadefinedrin thel-following elaims-.-,

Lclaimt.

1 A; collapsible:- container for: liquidrisaidicona tainerccomprisingi abase andz-aisidewalliof fiexi-iblel-li'quidetightmaterial'saroundisaidzbasee;saidtv sidewall havingnormally ani.upwardlysandxina ward-1y: arched disposition: relative rto theibase-a1whenrthes'container.is filled .withiliquidzand 'saidi sidewall: havingrana upper; peripherals margim overlying saidibaseinwardly of itheperiphery of said: aseand elevatediabover-said-rbase :at various:-heightsjlabove; saidi'base under: the: pressura of contained liquidagainst said sidewall ina accord ance: Withi the heights of thecontainedliquid above said base, and;a irestraining stay element' attached to:said base inwardof 'said upper-peripmeral margini and extending:diagonally-upward away from: said base' and outward tozam at tachmentito saidsidewall at'said upperpe=-- ripheral margin-for vertical swingingmovement'i. of "saidz-stayelement-"to accommodate changes inthe heightof said upper peripheralmargin abover said base; whereby shifting ofsaidi-upper peripheral 'margin'in thedirection laterally-outward oithecontainer is: restrainedby said" stay" ele merit underconditioned-greater height -of liqum above the base in the restrainedregion 0 "thee container asrcom-pared withotherr'regions'ioffztliefcontainer.

2. A collapsible container as 'd'efined iniclainr l' in-which-saidupper-peripheral margincomprisesarr annular collar of=deformable fiuidtight maw terial' relatively stiff as compared to-said 's'idewall forefiecting a:hoop stifieningzaction in said upper peripheral margin andprojecting upwardly from said sidewall at said upper peripheral marginfor holding in the space defined by said collar liquid at a levelproviding a hydrostatic head above said upper peripheral margin forexerting lifting pressure on said sidewall, and in which said stayelement is attached to said sidewall at said upper peripheral marginbelow the uppermost edge of the annular collar for resisting distortionof said collar and said sidewall laterally outward of the container.

3. A collapsible container for liquid, said container comprising a baseof flexible liquid-tight material and a sidewall of said material incontinuation of said base around its periphery and said sidewall havingnormally an upwardly and inwardly arched disposition relative to saidbase when the container is filled with liquid and said sidewall havingan upper peripheral margin overlying said base inwardly of the peripheryof said base and elevated above said base at various heights above saidbase under the pressure of contained liquid against said sidewall inaccordance with the height of the contained liquid above said base, incombination with a flexible stay of sheet material extending about theperiphery of said upper peripheral margin and attached to said baseinward of said upper peripheralmargin and extending diagonally upwardaway from said base and outward to an attachment to said sidewall atsaid upper peripheral margin for vertical swinging movement of said stayto accommodate changes in the height of said upper peripheral marginabove said base, whereby shifting of said upper peripheral margin in thedirection laterally outward of the container is restrained by said stayunder conditions of greater height of liquid above said base in therestrained region of the container as compared with other regions of thecontainer.

4. A collapsible container as defined in claim 3 in which said flexiblestay is peripherally continuous and substantially inextensible andimpervious throughout its peripheral extent providing with said sidewalland said base a closed annular chamber entirely about the periphery ofthe container for containing liquid independent of the main body ofliquid in the container, and in which said container includes a tubularstack projecting upwardly from said sidewall at said upper peripheralmargin in communication with said chamber for maintaining a hydrostatichead on the contained liquid in said chamber.

5. A collapsible container as defined in claim 3 in which said base isrectangular, and said sidewall forms straight sidewalls and roundcorners of the container, and in which said flexible stay has elongatedslits spaced-apart in the direction peripherally of said base andextending from a position in said stay adjacent said base to a positionin said stay adjacent said upper margin for passage of liquid throughsaid slits.

6. A collapsible container for liquid, said container comprising a baseand a sidewall of flexible liquid-tight material around said base, saidsidewall having normally an upwardly and inwardly arched dispositionrelative to the base when the container is filled with liquid and saidsidewall having an upper peripheral margin overlying said base inwardlyof the periphery of said base and elevated above said base at variousheights above said base under the pressure of contained liquid againstsaid sidewall in accordance with the height of the contained liquid 8above said base, means for maintaining a hydrostatic head of containedliquid for exerting lifting pressure on said sidewall to support thesidewall in its elevated condition above said base, and a flexible stayof sheet material extending about the periphery of said upper peripheralmargin and attached to said base inward of said' upper peripheral marginand extending diagonally upward away from said base and outward to anattachment to said sidewall at said upper peripheral margin for verticalswinging movement of said stay to accommodate changes in the height ofsaid upper peripheral margin above said base, whereby shifting of saidupper peripheral margin in the direction laterally outward of thecontainer is restrained by said stay under conditions of greater heightof liquid above said base in the restrained region of the container ascompared with other regions of the container.

7. A collapsible container for liquid, said container comprising a baseof flexible liquid-tight material, a collapsible wall of flexibleliquidtight material extending about said base and overlying said baseand having an upper margin inward of the periphery of said base, saidwall having normally an upwardly and inwardly arched dispositionrelative to said base when the container is filled with liquid, meansfor maintaining a hydrostatic head of contained liquid for exertinglifting pressure on said wall to support the latter in uprightdisposition, and a flexible stay of sheet material extending about theperiphery of said upper margin and diagonally from a position at saidupper margin to a position on said base inwardly of said upper marginand providing with said base and said wall an annular chamber forliquid, said stay being attached to said wall and said base only at saidpositions and being spaced from said wall between said positions forswinging movement relative to said base, and said stay being in a tautcondition under the upright disposition of said wall for restraininglocalized outward rolling and bowing of said wall under the hydrostaticpressure and having openings therein for admitting the main body ofliquid of the container to the space of said annular chamber forexerting said lifting pressure on said wall.

VICTOR H. HASSELQUIST.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 573,625 Ruffner Dec. 22, 18961,961,061 McCulloch May 29, 1934 2,084,236 Babb June 15, 1937 2,443,440Alvarez June 15, 1948

